My Wife's Sister

It had been a moth since I’d had sex with my wife. This was fine with her since she had found Brad, a guy with a twelve inch cock. Due to or open relationship, I was letting her sleep with Brad while I was secretly enlargeing my penis via a website that Brad had told me about. My cock was now 12 3/4 inches long and thick as a toddler’s arm. We were invited over to my in law’s house for a birthday party for my mother in law. She was turning 60. If you have read any of my other stories, you know that I fuck my mother in law(with my wife’s blessing). I have been getting tired of it lately, mostly due to a huge pussy farting problem she has. It’s not a turn on to listen to a pussy fart every time you pump your ccock in. A couple of times is one thing but ten or twelve minutes straight of pussy farting gets old fast. Well we went to the party and were having a good time, due to the drinks I was pouring down, when my wife’s sister Kathy showed up. She had always been the black sheep of the family and I noticed that Karen and her mom really treated her like shit. The first thing Susan, my mother in law said was, “Kathy, what have you done to your hair!?” She was blonde like her mom and sister but had cut it short and died it a dark brown with a reddish tint. I thought it looked good. I made my way over to her and noticed that she had also lost some weight. “Hey Kat, I think your hair looks nice! Did you lose some weight?” ” 30 pounds!” she said. “Thanks for noticing.” ” I see that it was in all the right places too.” I said eying her big tits. “Oh you’ve always liked my big tits haven’t you Dallas?” she said as she put her arms in front of herself and squeezed them together. She still wasn’t what you would call thin but she wasn’t fat either. “So what are your measurments now?” I asked. “42DD-30-36,” She whipered in my ear.”And all natural too!”, sahe said and bounced up and down a bit to make her tits shake. Karen saw us talking and made a bee line over to where we were standing. “Well Kat, glad you could make it.”, she said cooly. “You know I love mom’s parties!” Kathy said sarcasticly. Karen saw somebody across the room and went to say hi. “Let’s go out back and smoke some grass.” I said to Kathy and we made our way into the back yard and out behind the big ceder tree. I told her about Karen’s and my relationship and how we let eachother fuck other people and that it was starting to bother me. I had talked to karen and she said that she could never have just one man. She loved me and wanted to stay married but she still wanted to swing. “If you were my husband I would never let another woman touch you.” she said to me as we finished up the bowl. We went back inside and Karen found us,”There you are ,Dallas! I want you to meet Phil and Kim. There the couple I told you about, remember?” I shook their hands and Karen continued, “They want to get together next weekend. I thought we could go to the beach house.” Kathy was still standing there and Karen gave her a withering look. Kathy shook her head and left. I said,”The beach house sounds great honey,” And excused myself. I went after Kathy and we continued our conversation. We decided that neither of us wanted to be at the party. I told Karen that Kat would give me a ride home. She didn’t seem to happy about it but I was allready on my way out the door with Kathy right behind me. On the drive home we talked about how Karen and Susan had always treated Kathy like crap and given her shit about her weight. “Neither one of them noticed that i’ve lost 30 pounds!”, she said. “All my mom wanted to do is criticise my hair.” We got to our place and I invited her in for some bong tokes. She came in and we took a few tokes and one thing kind of led to another and we started kissing. “I don’t feel right about this, after all you’re married to my sister.” Kathy said when we came up for air. “I knew it!” Karen screamed as she flew into the room. “You brouhgt her here to fuck her!” ” Hold on a minute,” I said. “We aren’t fucking! I’ll admit that I kissed her but how many guys have you FUCKED since we’ve been married?” “Well you’ve fucked your share of women buster. I see you’ve been smoking pot too!” Karen didn’t like the fact that I got high. “Jesus Christ Karen , I’m a grown man and I’ll doo what I want in my own God damn house!” I was getting pissed off. “What, like fuck my sister? I didn’t know you liked fat chicks!” She sneered. “Fuck you!” Kathy yelled at her sister. ” If you wern’t so blind you’d have notice that I lost 30 pounds!” “Looks like you need to lose 30 more!” Karen shot back. What a bitch! “You know what Karen, I wasn’t planning on fucking Kathy at all, we were just kissing but all this talk about it has made me horny! Kathy , if your willing I’d love to have sex with you right now!” Karen said ” I dare you!” Kathy stood up and took off her shirt and bra. “Holy shit you have big tits!” I said. ” you have a great body Kat! Not like the damn near anorexic skinny bony shit that I’m used to!” Karen was fuming. Kathy took the rest of her clothes off and knelt in front of me and pulled down my pants. She sucked on my cock and it was hard in no time. Kathy looked at my new and imprved 12 3/4 inch cock. “Oh my God!! This is huge!” Karen couldn’t believe her eyes. “What happened to your dick?” She asked, her eyes wide. “I guess I’ve never been this turned on before!” I lied. I am never going to tell her about the penis enlargment website or the pills I took to increase the size of my cumshots. Kathy and I got into a 69 while Karen watched. I laid kKat back and slowly slid my cock into her dripping pussy. About 10 seconds later she was gushig juice out of her pussy. I fucked her for a few minutes and then placed my 12 3/4 in cock between tose 42DDs. She squeezed her tits together and I stoked her tits and a couple of minutes later I had the most incredible orgasm of my life! I shot stream after stream of cum on Kathy’s tits. We were laughing hysterically as I must have spurted 20 times. “Does he always cum like this?” Kathy asked Karen when I was finally done.” Umm well not really.” Karen said. “Kathy, I’ve never even come close to cumming like this. You must bring out the best in me.” Karen was too shoked to say a word. I got up and got a towel to wipe the cum off of Kathy’s massive mammeries.”Thanks Dallas,” she said. “Now fuck me some more!” She turned around and I fucked her doggie syle and enjoyed watching her plump ass jiggle as I polwed her. It was soft and warm and much nicer than a bony ass. She turned on her back and said she wanted to look into my eyes as I fucked her. “Oh God Dallas this feels so good! Oh yeah I’m gonna cum! Shoot inside me baby I don’t want another mess!” I felt her pussy gush a ton of hot liquid as she came. I shot my load Deep inside her twat at the same time as she was ccoming and we looked deep into eachother’s eyes. “Oh Dallas, I don’t want to share you with anybody! That was so good! I’ve never had such intense orgasms!” “Neither have I, Kat” I said aas I smiled at Karen.